SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '461323db29aca773a7af6c6917e6bee572e9920c3a6ccdbb347042071f2ef7e7' 
  AND token = '+a7qt6t8BkzgYCrtHJh0LVSU1CYnEGMpJxIO8IEkc20=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}